QSqlRelationalTableModel只填充前256条记录

I have the following simple model using PyQt5, sqlite3 and python3.5.2.

我使用PyQt5、sqlite3和python3.5.2建立了以下简单的模型。

class choicesModel(QDialog):
    def __init__(self, parent=None):
        super(choicesModel, self).__init__()

        query = QSqlQuery()
        query.prepare("SELECT COUNT(*) FROM resident_choices")
        query.exec_()
        query.next()
        dbrows = query.value(0)
        print("rows in db: ", dbrows)

        self.choicesModel = QSqlRelationalTableModel(self)
        self.choicesModel.setEditStrategy(QSqlTableModel.OnManualSubmit)
        self.choicesModel.setTable("resident_choices")
        self.choicesModel.select()
        rows = self.choicesModel.rowCount()
        print("rows returned by model.select(): ", rows)

Executing the model produces the following output:

执行模型产生如下输出:

rows in db: 831

行db:831

rows after model.select(): 256

行model.select后():256

It appears that the initial select only populates the first 256 records. Is this an sqlite3 issue and if so how do I populate all records (the db only has about 850 records total). If not how can I force all records to be loaded?

似乎初始选择只填充前256条记录。这是一个sqlite3问题吗?如果是，我如何填充所有记录(db总共只有850条记录)。如果不是，我怎样才能强制加载所有记录?

The upshot is that using a proxymodel and proxy view does not initially show all records until I change the proxy filter condition - that is, I have to trigger the loading of the rest of the records.

其结果是，使用proxymodel和proxy视图最初不会显示所有记录，直到我更改了proxy filter条件——也就是说，我必须触发加载其余记录。

1 个解决方案

#1

The number of records is hard-coded as #define QSQL_PREFETCH 255 in the QSqlQueryModel class. To override it, you will have to explicitly fetch all the rows yourself:

在QSqlQueryModel类中，记录的数量被硬编码为#define QSQL_PREFETCH 255。要重写它，您必须自己显式地获取所有行:

while self.choicesModel.canFetchMore():
    self.choicesModel.fetchMore()

You will probably need to run code like this every time the model is updated, so it might be better to create your own sub-class and reimplement fetchMore.

每次模型更新时，您可能需要像这样运行代码，因此最好创建自己的子类并重新实现fetchMore。

#1